In the field of silver halide photographic light-sensitive materials, silver images are suitable for recording information which must be stored over a long period, because the silver images are faster than the so-called color images (dye images). However, the silver images tend to deteriorate with the passage of time, and it has been found that the tendency is great when using a water impermeable support such as a plastic film, etc. Water impermeable supports such as plastic films, etc., are suitable for long period storage because they generally have higher strength than supports such as paper or cloth. However, they are not desirable because they result in increasing the deterioration of silver images as described above. Deterioration of silver images on the water impermeable supports has been reported in Photographic Science and Engineering, Vol. 7, pages 253-261 (1963) and Journal of Applied Photographic Engineering, Vol. 7 (No. 1), pages 1-9 (1981), etc.
An example of a technique for preventing deterioration of silver images on water impermeable supports involves a process which is carried out with compounds described in British Patent (publication) No. 2,019,024A. However, this is not sufficient to prevent deterioration of silver images in a severe oxidative gas or an oily paint atmosphere.